At least one hard disk drive (HDD) is used in almost all computer system operations. In fact, most computing systems are not operational without some type of HDD to store the most basic computing information such as the boot operation, the operating system, the applications, and the like. In general, the HDD is a device which may or may not be removable, but without which the computing system will generally not operate.
The HDD typically includes at least one actuator arm. The actuator arm extends over a spinning magnetic disk and is used to control the position of a read/write head relative to the spinning magnetic disk. An actuator arm may be coupled with a suspension base plate or head suspension. Techniques used to couple a suspension base plate with an actuator arm may result in a portion of the suspension base plate and/or a portion of the actuator arm being deformed. Such a deformation can cause changes in the desired position orientation of the suspension known as z-height variations. The deformation can also result in changes to the spring characteristics of the suspension known as gram load changes. The deformations can occur on one or more actuator arm in the HDD and the deformations cause different results in different actuator arms in the HDD. For example, an inner actuator arm may have a greater increase in gram load than an outer actuator arm. These results cause undesirable performance in the HDD.